Devices and methods for locating and visualizing underwater objects

ABSTRACT

Sonar devices for detecting underwater objects are provided whereby a set of angled ultrasound transducers are employed to sense ultrasound signals from a plurality of different spatial regions. The angled ultrasound transducers may include a first pair of side-viewing ultrasound transducers and a second pair of ultrasound transducers configured for interrogating forward and reverse directions. The ultrasound signals from the set of angled ultrasound transducers may be processed to identify the presence of underwater objects in each spatial region, and the resulting identified underwater objects may be displayed, on a per-region basis, on a user interface. The ultrasound signals may additionally or alternatively be processed to generate a topographical model of the bed surface, and to generate a topographical surface image based on the three-dimensional topographical model. The topographical surface image may be displayed as a fly-over animation.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S.application Ser. No. 16/048,755, titled “DEVICES AND METHODS FORLOCATING AND VISUALIZING UNDERWATER OBJECTS” and filed Jul. 30, 2018,which is a continuation of and claims priority to U.S. application Ser.No. 15/700,918, titled “DEVICES AND METHODS FOR LOCATING AND VISUALIZINGUNDERWATER OBJECTS” and filed Sep. 11, 2017, which is a continuation ofand claims priority to U.S. application Ser. No. 15/189,650, titled“DEVICES AND METHODS FOR LOCATING AND VISUALIZING UNDERWATER OBJECTS”and filed Jun. 22, 2016, now issued as U.S. Pat. No. 9,759,813, whichclaims priority to U.S. Provisional Application No. 62/182,989, titled“DEVICES AND METHODS FOR LOCATING AND VISUALIZING UNDERWATER OBJECTS”and filed Jun. 22, 2015, the entire contents of each being incorporatedherein by reference in their entireties.

BACKGROUND

The present disclosure relates to sonar device and methods detection ofunderwater objects.

Fish finding sonar devices typically employ a single, dual-frequencytransducer for sonar detection, where the higher frequency is used forclarity in shallower waters, and the lower frequency is employed toachieve penetration in deeper waters. The lower frequency casts apowerful, wide beam that can more easily detect underwater objects at ornear the bottom of a body of water, however, with the beam beingrelatively wide, the increased depth penetration comes at the expense oflateral spatial resolution. The higher frequency beam, although beingincapable of deep penetration, provides a much narrower beam to betterdetect structural changes and suspended fish. A user may switch betweenthe two frequencies depending on the environment they are in. A commonfrequency pairing for a low-cost fish finder is 50/200 kHz, where the 50kHz signal would have a relatively wide angle (40+ degrees) capable ofdeep penetration with the higher 200 kHz signal having a much narrowerbeam (˜20 degrees) that is only effective in shallower waters.

SUMMARY

Sonar devices for detecting underwater objects are provided whereby aset of angled ultrasound transducers are employed to sense ultrasoundsignals from a plurality of different spatial regions. The angledultrasound transducers may include a first pair of side-viewingultrasound transducers and a second pair of ultrasound transducersconfigured for interrogating forward and reverse directions. Theultrasound signals from the set of angled ultrasound transducers may beprocessed to identify the presence of underwater objects in each spatialregion, and the resulting identified underwater objects may bedisplayed, on a per-region basis, on a user interface. The ultrasoundsignals may additionally or alternatively be processed to generate atopographical model of the bed surface, and to generate a topographicalsurface image based on the three-dimensional topographical model. Thetopographical surface image may be displayed as a fly-over animation.

Accordingly, in a first aspect, there is provided a sonar device fordetecting underwater objects, the sonar device comprising:

a housing;

a plurality of angled ultrasound transducers supported by said housing;

processing circuitry provided within said housing, said processingcircuitry comprising an ultrasound transceiver that is operablyconnected to said angled ultrasound transducers, said processingcircuitry further comprising an interface for communicating with aremote computing device, and wherein said processing circuitry isconnected or connectable to a power source;

wherein at least two of said ultrasound transducers are angledultrasound transducers having respective ultrasound beam axes that aredirected at an acute angle relative to a primary axis of said sonardevice, such that each angled transducer is configured to interrogate adifferent spatial region; and

wherein said sonar device is configured to float in a stable orientationsuch that said primary axis is vertically oriented in still water.

In another aspect, there is provided a system for detecting and locatingunderwater objects, the system comprising:

a remote computing device; and

a sonar device configured as described above;

wherein one of said remote computing device and said sonar device isconfigured to:

-   -   obtain signals from the angled ultrasound transducers, wherein        the signals are received in response to ultrasound beams emitted        from the angled transducers; and    -   process the signals to identify, within each spatial region, the        presence of one or more underwater objects; and

wherein said remote computing device is configured to display, on a userinterface, a visual representation indicating, on a per-region basis,the presence of the underwater objects detected within each the spatialregion.

In another aspect, there is provided a computer-implemented method ofgenerating and presenting sonar data, the method comprising:

receiving, on the remote computing device, sonar data transmitted from asonar device configured according to claim 1, the sonar data comprisingsignals obtained from the angled ultrasound transducers, the signalshaving been obtained in response to ultrasound beams emitted from theangled ultrasound transducers;

processing the signals to identify, within each spatial region, thepresence of one or more underwater objects;

displaying, on a user interface associated with remote computing device,a visual representation indicating, on a per-region basis, the presenceof the underwater objects detected within each the spatial region.

In another aspect, there is provided a system for measuring anddisplaying a visualization of a bed surface of a body of water, thesystem comprising:

a remote computing device; and

a sonar device configured as described above;

wherein said sonar device is configured to obtain signals from a pair ofangled ultrasound transducers and from said central ultrasoundtransducer, wherein the signals are received in response to ultrasoundbeams emitted by the ultrasound transducers; and

wherein one of said remote computing device and said sonar device isconfigured to:

-   -   process the signal from the central ultrasound transducer to        determine, a central bed depth measure providing an estimate of        bed depth within the central region; and    -   process the signals from the pair of angled ultrasound        transducers to determine lateral bed depth measures, each        lateral bed depth measure providing an estimate of bed depth        within a respective lateral region; and wherein said remote        computing device is configured to:    -   process the central bed depth measures and the lateral bed depth        measures associated with a plurality of locations in a        longitudinal direction to generate a three-dimensional        topographical model of the bed surface; and    -   render a topographical surface image based on the        three-dimensional topographical model and displaying the        topographical surface image on a user interface.

In another aspect, there is provided a computer-implemented method ofmeasuring and displaying a visualization of a bed surface of a body ofwater, the method comprising:

receiving, on the remote computing device, signals a sonar deviceconfigured as described above, the signals having been obtained from apair of angled ultrasound transducers and from a central ultrasoundtransducer at a plurality of locations in a longitudinal direction,wherein the signals are received in response to ultrasound beams emittedby the ultrasound transducers; and processing the signal from thecentral ultrasound transducer to determine, at each location, a centralbed depth measure providing an estimate of bed depth within the centralregion; and

processing the signals from the pair of angled ultrasound transducers todetermine, at each longitudinal location, lateral bed depth measures,each lateral bed depth measure providing an estimate of bed depth withina respective lateral region;

processing the central bed depth measures and the lateral bed depthmeasures associated with the locations to generate a three-dimensionaltopographical model of the bed surface; and

rendering a topographical surface image based on the three-dimensionaltopographical model and displaying the topographical surface image on auser interface.

A further understanding of the functional and advantageous aspects ofthe disclosure can be realized by reference to the following detaileddescription and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described, by way of example only, withreference to the drawings, in which:

FIG. 1 shows an example system for identifying underwater objects with asonar device.

FIGS. 2A-F shows various example transducer configurations of a sonardevice.

FIGS. 3A-F show several views of the bottom portion of a housing of anexample sonar device.

FIG. 4 illustrates an example of configuration of an ultrasound beamemployed for detection of underwater objects.

FIG. 5 is a flow chart describing an example method of visualizing thespatial locations of underwater objects identified by a plurality ofultrasound transducers, the transducers being configured to detectunderwater objects in different spatial directions.

FIGS. 6A and 6B show example user interface screenshots illustratingspatial-resolved detection and identification of underwater objects.

FIG. 7 is a flow chart illustrating an example method for rendering atopographical surface image of a bed surface on a user interface.

FIG. 8 is a screenshot of an example rendering of a topographical imageof a bed surface.

DETAILED DESCRIPTION

Various embodiments and aspects of the disclosure will be described withreference to details discussed below. The following description anddrawings are illustrative of the disclosure and are not to be construedas limiting the disclosure. Numerous specific details are described toprovide a thorough understanding of various embodiments of the presentdisclosure. However, in certain instances, well-known or conventionaldetails are not described in order to provide a concise discussion ofembodiments of the present disclosure.

As used herein, the terms “comprises” and “comprising” are to beconstrued as being inclusive and open ended, and not exclusive.Specifically, when used in the specification and claims, the terms“comprises” and “comprising” and variations thereof mean the specifiedfeatures, steps or components are included. These terms are not to beinterpreted to exclude the presence of other features, steps orcomponents.

As used herein, the term “exemplary” means “serving as an example,instance, or illustration,” and should not be construed as preferred oradvantageous over other configurations disclosed herein.

As used herein, the terms “about” and “approximately” are meant to covervariations that may exist in the upper and lower limits of the ranges ofvalues, such as variations in properties, parameters, and dimensions.Unless otherwise specified, the terms “about” and “approximately” meanplus or minus 25 percent or less.

It is to be understood that unless otherwise specified, any specifiedrange or group is as a shorthand way of referring to each and everymember of a range or group individually, as well as each and everypossible sub-range or sub-group encompassed therein and similarly withrespect to any sub-ranges or sub-groups therein. Unless otherwisespecified, the present disclosure relates to and explicitly incorporateseach and every specific member and combination of sub-ranges orsub-groups.

As used herein, the term “on the order of”, when used in conjunctionwith a quantity or parameter, refers to a range spanning approximatelyone tenth to ten times the stated quantity or parameter.

In one example embodiment, a sonar device is provided for locating thepresence of underwater objects, such as one or more fish, in a pluralityof spatial regions. FIG. 1 shows an example implementation of a systemincluding a sonar device 100 for use in locating the presence ofunderwater objects. Sonar device 100 includes ultrasound transducers110A-110C secured in a housing 120, where the ultrasound transducers110A-110C are supported and oriented such that their respectiveultrasound beam axes 112A-112C are directed in different directions forinterrogating different spatial regions 114A-1140. Each ultrasoundtransducer is connected to an ultrasound transceiver 130, which providesexcitation pulses to the ultrasound transducers, and receives ultrasoundsignals responsively generated by reflections from underwater objects.

Housing 120 contains and protects internal electronics and processingcircuitry. The shape of the housing 120 need not be spherical as shownin FIG. 1.

The housing 120 may be waterproof and constructed of plastic or anotherbuoyant material. It will be understood that there are numerous sizes,shapes, and materials that could be utilized for the housing in theembodiments of the present disclosure. The housing 120 can generallytake on a variety of shapes, provided that it floats in a stable andpre-configured orientation.

The sonar device 100 is configured, by selection of the housing shape,and the weight distribution of the housing and its supported components,such that it floats in a stable and pre-selected configuration. Thesonar device 100 is shown in FIG. 1 as floating in still water 101,whereby a primary axis 105 associated with the sonar device 100 isoriented in the vertical orientation. The primary axis 105 of the sonardevice tilts relative to the vertical direction when the sonar device isperturbed.

The example embodiment illustrated in FIG. 1 shows the transceiver 130connected, through bus or electrical path 135, to processing circuitrythat includes processor 140 and memory 150, and to communicationsinterface 160 and power source 170. Transceiver 130 controls ultrasoundtransducers 110A-110C to emit excitation ultrasound energy therefromalong respective ultrasound beam axes 112A-112C, and transceiver 130receives signals from the ultrasound transducers 110A-110C in responseto ultrasound waves reflected by underwater objects. In one exampleimplementation, transceiver 130 receives raw sonar electrical signalsfrom ultrasound transducers 110A-110C.

Processor 140 is configured, based on executable instructions stored inmemory 150, to control the transmission of sonar data, viacommunications interface 160, to the remote computing device 200. Thesonar data that is transmitted to the remote computing device 200 may beraw sonar data (e.g. digitized raw data suitable for transmission over awireless communication channel) or data that is pre-processed by theprocessor 140. For example, processor 140 may be programmed to identifythe presence, and optionally depth, associated with one or more objectsin each spatial region 114A-114C. Alternatively, such processing may beperformed remotely by remote computing device 200, as described furtherbelow.

As shown in FIG. 1, communications interface 160 may be wirelessinterfacing device, which employs antenna 180 to transmit and optionallyreceive wireless signals 185. For example, communications interface 160may include a wireless network transceivers (e.g., Wi-Fi™, Bluetooth®,cellular), wired network interfaces (e.g., a CAT-type interface), USB,FireWire, or other known interfaces. A wireless housing may be direct(directly between the sonar device 100 and the remote computing device200) or indirectly (e.g. where each device remotely connects to a remoteserver through a cellular network). A wired connection may befacilitated thought a suitable water-tight connector that is externallyaccessible on the housing.

As shown in FIG. 1, sonar device 100 includes, or is connectable to, apower supply 170. A rechargeable or non-rechargeable battery may be usedto provide power. The power may also be provided by an external powersource, such as an AC adapter or a powered docking cradle thatsupplements and/or recharges a battery. Alternatively, power may beprovided through a solar cell device, such as a photovoltaic array.

Referring again to FIG. 1, ultrasound transducers 110A-110C may beformed from a wide range of piezoelectric materials. For example, theultrasound transducers 110A-110C may be formed from ceramicpiezoelectric materials. In some example embodiments, the ultrasoundtransducers 110A-110C may be operable at one or more frequencies. Forexample, one or more of ultrasound transducers 110A-110C are operated atdual frequencies, in order to produce respective ultrasound beams thathave different angular bandwidths and different penetration depthswithin the water. In one example implementation, the sonar device 100may be configured such that the ultrasound transducers 110A-110C areoperated at a first frequency of approximately 300 kHz and a secondfrequency of approximately 500 kHz.

As shown in FIG. 1, the housing 120 may be configured with a tetherlocation 190 that is configured for the tethering of a line or cable(such as a fishing line) thereto. For example, the tether location 190may include an eyelet, hook, clamp, or any other line tetheringmechanism, such as those commonly employed in fishing lures and bobbers.

The sonar device 100 may be configured to collect one or more additionalforms of information in addition to signals associated with ultrasounddetection. One of ordinary skill in the art would appreciate thatcomponents of the system could be configured to collect a variety ofdifferent information, and embodiments of the present invention arecontemplated, and may be adapted, for use with a variety of additionalforms of collectable information. For example, the sonar device 100 mayfurther include one or more additional sensors for collecting additionalsignals and/or sensor data. For example, one or more additional sensorsmay be selected from the non-limiting list including a thermometer, aspeed sensor, an accelerometer, and a Global Positioning System device.One of ordinary skill in the art would appreciate that there arenumerous types of sensors that could be utilized with embodiments of thepresent disclosure. The sonar device 100 may further include additionalcomponents, not shown in FIG. 1, including, but not limited to, one ormore of a data storage device, an indicator light, and an auditorysignal generation device.

Sonar device 100 may also optionally include a GPS receiver fordetermining an absolute or relative location of the sonar device, and/ora speed or velocity of the sonar device. The GPS receiver can alsoemploy other geo-positioning mechanisms, including, but not limited to,triangulation, assisted OPS (AGPS), E-OTD, CI, SAI, ETA, BSS or thelike, to further determine the physical location of the sonar device100.

In the example system shown in FIG. 1, sonar device 200 is connected, orconnectable, to a remote computing device 200. The sonar device 200employs ultrasound transducers 110A-1100 to acoustically interrogate aplurality of underwater spatial regions 114A-114C. Remote computingdevice 200 communicates with sonar device 100 in order to receiveinformation collected by the sonar device, and to present informationrelated to the detected underwater objects on a display.

It will be understood that remote computing device may be any devicecapable of processing the received signals and displaying, orinterfacing with an external display, for the presentation ofinformation to a user. Non-limiting examples of remote computing devicesinclude smartphones, tablets, laptop computers, smartwatches, and otherportable computing devices. Another example of a remote computing deviceis a computing system residing on, or integrated with, a vessel. Thephrase “remote” refers to two devices that are physically separated andconnect through a wired or wireless interface.

FIG. 1 illustrates an example embodiment of the computer hardwareassociated with remote computing device 200. Remote computing device 200includes one or more processors 210 in communication with memory 220 viaa bus 205. Remote computing device 200 includes a communicationinterfaces 230 for communicating with sonar device 100, a display 240,an optional internal or external storage media 250, and an optionalinput/output interfaces 260. Remote computing device 200 also includes,or is connectable to, a power supply. A rechargeable or non-rechargeablebattery may be used to provide power. The power may also be provided byan external power source, such as an AC adapter or a powered dockingcradle that supplements and/or recharges a battery.

The processor 210 include may include an arithmetic logic unit, amicroprocessor, a general purpose controller, or some other processorarray to perform computations and/or provide electronic display signalsto a display device. Processor 210 is shown coupled to the bus 205 forcommunication with the other components of the remote computing device200. Although only a single processor 210 is shown in FIG. 1, multipleprocessors may be included and each processor may include a singleprocessing core or multiple interconnected processing cores. Processor210 may be capable of processing sonar data and rendering imagesdisplayable on a display device.

Memory 220 may include a RAM, a ROM, and other storage means. Memory 220illustrates another example of computer storage media for storage ofinformation such as computer readable instructions, data structures,program modules or other data. Memory 220 may store a basic input/outputsystem (“BIOS”) or firmware for controlling low-level operation ofremote computing device 200. The memory 220 may also store an operatingsystem 241 for controlling the operation of remote computing device 200.It will be appreciated that this component may include a general purposeoperating system such as a version of Windows, Mac OS, UNIX, or LINUX™,or a specialized mobile client communication operating system such asiOS™, Android™, Windows Mobile™, or the Symbian® operating system, or anembedded operating system such as Windows CE. The operating system mayinclude, or interface with a Java virtual machine module that enablescontrol of hardware components and/or operating system operations viaJava application programs.

Remote computing device may be configured to execute one or moreapplications or “apps”. Such applications may include computerexecutable instructions stored by memory 220, and which, when executedby remote computing device 200, perform one or more algorithms disclosedherein for the generation and presentation of information on a userinterface, where the information pertains to the detection of one ormore underwater objects (optionally including the bed surface 102).

A communications interface 230 is provided for communication with one ormore sonar devices 100, as described above in the context forcommunications interface 160. Communications interface 230 may includedevices for communicating with other electronic devices.

Display 240 may be any suitable display device, such as a liquid crystaldisplay (LCD), gas plasma, light emitting diode (LED), e-ink, or anyother type of display used with a computing device. Display 240 may alsoinclude a touch sensitive screen arranged to receive input from anobject such as a stylus or a digit from a human hand. In another exampleimplementation, remote computing device 200 need not include a display,but may be connected or connectable to an external display device.

As shown in FIG. 1, remote computing device 200 may also include aninternal or external storage medium 250, such as removable flash memory,a hard disk drive, or another external storage device. In oneembodiment, a portion of the instructions executable by the processor210 may also be located external to remote computing device 200.

Remote computing device 200 may also include input/output interfaces 260for communicating with external devices, such as a headset, smartwatchor other input or output devices not shown in FIG. 1. Remote computingdevice 200 may also include a GPS receiver.

Remote computing device 200 may optionally communicate with a basestation (not shown), or directly with another computing device. Forexample, a network interface device (not shown) may be included thatprovides circuitry for coupling remote computing device 200 to one ormore networks, and is constructed for use with one or more communicationprotocols and technologies including, but not limited to, global systemfor mobile communication (GSM), code division multiple access (CDMA),time division multiple access (TDMA), user datagram protocol (UDP),transmission control protocol/Internet protocol (TCP/IP), SMS, generalpacket radio service (GPRS), WAP, ultra wide band (UWB), IEEE 802.16Worldwide Interoperability for Microwave Access (WiMax), SIP/RTP,Bluetooth™, infrared, Wi-Fi, Zigbee, or any of a variety of otherwireless communication protocols.

It is to be understood that the example system shown in FIG. 1 is notintended to be limited to the components that may be employed in a givenimplementation. Although only one of each component is illustrated inFIG. 1, any number of each component can be included. For example, thesonar device 100 and/or the remote computing device 200 may include oneor more additional processors. In another example, a remote computingdevice may contain a number of different data storage media 250.

Although FIG. 1 illustrates an example embodiment that includes a singlesonar device, it will be understood that in other example embodiments, aplurality of sonar devices may be connected to the remote computingdevice 200.

While some embodiments can be implemented in computer hardware, variousembodiments are capable of being distributed as a computing product in avariety of forms and are capable of being applied regardless of theparticular type of machine or computer readable media used to actuallyeffect the distribution. At least some aspects disclosed can beembodied, at least in part, in software. That is, the techniques may becarried out in a computer system or other data processing system inresponse to its processor, such as a microprocessor, executing sequencesof instructions contained in a memory, such as ROM, volatile RAM,non-volatile memory, cache or a remote storage device.

A computer readable storage medium can be used to store software anddata which when executed by a data processing system causes the systemto perform various methods. The executable software and data may bestored in various places including for example ROM, volatile RAM,nonvolatile memory and/or cache. Portions of this software and/or datamay be stored in any one of these storage devices. As used herein, thephrases “computer readable material” and “computer readable storagemedium” refers to all computer-readable media, except for a transitorypropagating signal per se.

Referring again to FIG. 1, the sonar device 100 illustrates anon-limiting example transducer configuration involving three ultrasoundtransducers 110A-110C, where each transducer is oriented with itsultrasound beam axis directed in a unique direction, for theinterrogation of different spatial regions. The example configurationshown in FIG. 1 illustrates an embodiment in which the angled ultrasoundtransducers 110A and 1108 form a pair of angled ultrasound transducerslocated on opposite sides of the primary axis 105. The pair of angledultrasound transducers 110A and 110B are thus configured to interrogaterespective lateral regions 114A and 114B on either side of the device.

In various embodiments, the sonar device includes a plurality of angledultrasound transducers, such as angled ultrasound transducers 110A and110B, and may optionally include a central ultrasound transducer, suchas central ultrasound transducer 110C. As shown in FIG. 1, the angledultrasound transducers and oriented such that their respectiveultrasound beam axes are directed outwardly at an acute angle relativeto the primary axis 105.

Although the angular bandwidth of the angled transducers 110A and 110Bare shown in FIG. 1 as non-overlapping, it will be understood that oneor more of the frequencies of the angled ultrasound transducers, andtheir respective angles relative to the primary axis 105, may be variedin order to achieve spatial overlap. In one non-limiting exampleimplementation, the acute angles of the angled transducers, relative tothe primary axis 105, may be selected to lie between 20° and 30°.

As noted above, the sonar device 100 may optionally include a centraltransducer 110C that is oriented such that its ultrasound beam axis 112Cis parallel to, or directed along, the primary axis 105. As describedbelow, the central ultrasound transducer 110C may be employed to detectthe presence of underwater objects directly underneath the sonar device,in addition to the detection in the lateral spatial regions associatedwith the angled ultrasound transducers. The central ultrasoundtransducer 110C may also optionally be employed to provide a bed depthmeasure associated with the depth of the bed surface 102. The centralultrasound transducer may be provided between, or may be surrounded by,the angled transducers. Alternatively, the central ultrasound transducermay be located adjacent to the angled transducers.

FIGS. 2A-2F illustrate a number of example configurations of the angledtransducers, where the housing 120 is shown from below, viewed along theprimary axis. FIG. 2A shows an example configuration in which atriangular array of transducers 110 are provided. FIG. 2B shows anotherexample configuration involving a pair of adjacent angled transducers,located on opposing sides of the primary axis. FIG. 2C shows theangled-transducer pair of FIG. 2B with an additional central transducercentered therebetween. FIG. 2D shows the triangular array of angledtransducers of FIG. 2A, with an additional central transducer centeredtherebetween. FIG. 2E shows an example configuration involving a squarearray of angled transducers, where each angled transducer is angled tointerrogated a separate spatial quadrant. FIG. 2F shows yet anotherexample configuration whereby a pentagonal array of transducers isprovided.

As shown in FIGS. 2A-2F, the arrays of angled transducers may becentered on the primary axis. Also, as shown in the figures, the angledtransducers may be evenly spaced around the primary axis. In otherexample embodiments, the transducers may be unevenly spaced, forexample, in the form of a rectangular array, as opposed to the squarearray of FIG. 2E.

FIGS. 2A-2E show the presence of the tether location 190. Referring nowto FIG. 2E, by way of example, the tether location 190 and the primaryaxis 105 define a longitudinal plane 195, indicative a towing directionof the sonar device when the sonar device is towed by a tether attachedto tether location 190. As shown in FIG. 2E, a first pair of angledtransducers 116A and 116B may be located on opposing sides of thelongitudinal plane 195, such that the first pair of transducers 116A and116B scans the lateral directions (left and right; port and starboard)as the sonar device is towed. A second pair of angled transducers 118Aand 118B may be provided such that their respective ultrasound beam axesare directed within the longitudinal plane (or approximately within theplane, for example within ±1°, ±2°, or ±5°), such that the second pairof angled transducers 118A and 118B are configured to scan thelongitudinal directions (forward and reverse; bow and stern) when thesonar device is towed.

As shown in various embodiments illustrated in FIGS. 2A-2F, the angledultrasound transducers may be provided as discrete circumferentialarray. The circumferential array may be located such that it surrounds,and is optionally centered on, the primary axis (and/or a centralultrasound transducer). In some non-limiting example embodiments, theangled ultrasound transducers of the circumferential array may include3, 4, 5, 6, 7, 8, 9 or 10 evenly spaced transducers. In one exampleimplementation, the array of angled ultrasound transducers may besymmetrically arranged relative to the longitudinal plane 190 within asuitable spatial tolerance (e.g. within ±100 μm, ±200 μm, ±500 μm, ±1mm, ±2 mm or ±5 mm). In one example implementation, the array of angledtransducers may be spatially arranged such that their net center of massis located on or near (e.g. within ±100 μm, ±200 μm, ±500 μm, ±1 mm, ±2mm or ±5 mm) the primary axis.

Referring now to FIGS. 3A-3F, an example implementation of the bottomportion of an example housing 120 of a sonar device is shown. Examplehousing 120 includes receptacles 122 for housing a set of four angledultrasound transducers and a central ultrasound transducer. Housing 120also includes an external tether location 190. In FIG. 3C, externalplanar surfaces 124, thought which ultrasound energy is to be emittedand collected by the ultrasound transducers, are shown in the lowerportion of the external surface of the example housing 120. FIGS. 3D-3Fshow additional views of the housing 120, where two electronicsplatforms 142 and 144 are shown, with antenna 180 provided in an upperportion of the housing, above the water line when the sonar device isfloated in water. Lower platform 144 includes through-holes forconnecting the electronics (not shown) to the ultrasound transducers.

The preceding example embodiments have disclosed sonar devices, andassociated systems, where the sonar device includes a plurality ofangled transducers, and optionally a central transducer, where theultrasound transducers are configured to interrogate differentunderwater spatial regions.

Referring now to FIG. 4, an example method of detection of underwaterobjects, using a multi-transducer sonar device, is described. In theexample configuration illustrated in FIG. 4, the example sonar deviceincludes two angled ultrasound transducers (left and right) and acentral transducer. The central transducer is directed in a downwarddirection, while the left and right transducers are at a 30 degree anglefrom the primary axis. In the present non-limiting example, eachtransducer is a dual-frequency transducer exhibiting a 12-20° beam angle(12° for high frequency operation and 20° for low frequency operation).Each transducer generates a receive signal integrating the response overits entire coverage area. A conventional pulse-echo depth soundingmethod may then be employed, using the shallowest point as the depth,and then detecting the relative depth of any underwater objects (e.g.fish) within this depth range.

FIG. 4 shows the ultrasound beam emitted by the central transducer (thelateral beams from the angled transducer pair are not shown), showingthe beam angle associated with the 20° coverage area when sounded withlow frequency central beam.

As can be seen from the figure, the shallowest detected point in theactual bottom contour is 21.6 ft, while the deepest detected point is24.4 ft. Because the transducer integrates over its entire coveragearea, the calculated depth measure will be 21.6 ft, the shallowest pointit detects. Once the depth has been determined, the underwater objectdetection algorithm searches for underwater objects up to the processeddepth, in this case, searching for underwater objects within itsdetection area that is shallower than the processed depth. In the abovegraphic, there is only one fish within the detection area at a depthless than 21.6 ft, being the fish at 16.5 ft. The fish at 13.5 ft isoutside of the ultrasound beams coverage area and will not be detected.The fish at 22.7 ft is deeper than the processed depth of 21.6 ft andthus, will not be detected.

The same method may then be applied to the signals received from thelateral pair of angled transducers in order to search for, andoptionally determine the depth of, underwater objects within the lateralspatial regions associated with the angled transducers. The left andright transducers may operate under the same constraints as the centraltransducer, but are adjusted for their angle relative to the primaryaxis. Both angled transducers process depth as the shallowest pointwithin their respective coverage areas and find fish up to theirprocessed depths, as in the method described above.

The aforementioned example method thus provides information pertainingto the presence, and optional depth, of underwater objects in aplurality of spatial regions, with each spatial region associated with adifferent ultrasound transducer. This spatial information may beemployed to provide a user with a visualization of the spatial locationsof one or more detected underwater objects.

FIG. 5 provides a flow chart illustrating an example embodiment ofprocessing the data to obtain spatial information associated with thedetection of underwater objects, and presenting this information to auser on a user interface associated with the remote computing device. Inoptional step 300, a data connection is established with the sonardevice (alternatively, a data connection need not be established if thesonar device is broadcasting data according to a wireless protocol thatdoes not require a connection). The signals from the angled transducers,and optionally from a central transducer (if present), and then receivedin step 305. These signals are processed, in step 310, in order toidentify the presence of, and optionally the depth of, underwaterobjects within the spatial region (e.g. field of view) associated witheach transducer (for example, using the example methods describedabove). In step 315, the presence, and optional depth measure,associated with each detected underwater object, is displayed on a userinterface associated with the remote computing device (e.g. displayed ona display integrated with, or connected to, the remote computingdevice), where a visual representation of the spatial regions isprovided, indicating the presence and optional depth of the detectedunderwater objects on a per-region basis.

In one example embodiment, the spatial regions are shown, on the userinterface, in a manner that represents their relative location. Forexample, if a sonar device is employed having four angled transducers,with four quadrants associated therewith, a graphical display may showfour regions positioned according to the relative positions of the fourquadrants, with each region showing information associated with thepresence of underwater objects detected therein. In other words, thegeometrical arrangement of the regions shown in the visualization on theuser interface may correlate with the geometrical arrangement of thetransducers of the sonar device. In embodiments in which a centraltransducer is employed along with angled transducers, the visualizationmay show a central region associated with the central transducer,surrounded by regions associated with the angled transducers.

The user interface may also be configured to display depth informationassociated with one or more of the transducers. For example, in oneexample embodiment, depth information may be provided based on a beddepth measure obtained from the central transducer. In another exampleembodiment, depth information associated with any transducer may beselectively displayed based on input from a user.

FIGS. 6A and 6B show two example implementations of a visualizationaccording to the method described in FIG. 5. In FIG. 6A, a smartphone isshown displaying a visualization showing five quadrants 400A, 400B,400C, 400D and 400E associated with geometrical arrangement of fivetransducers arranged according to the configuration shown in FIGS. 3A-F.Fish identified based on the signals obtained from the varioustransducers of the sonar device are shown in their associated regions,along with depth information. The right image shows a depth-based viewof the highlighted quadrant, with a visualization of the different fishdepths.

FIG. 68 illustrates an example implementation in the visualization isconfigured such that if one or more transducers locates an underwaterobject (e.g. a fish), the respective quadrant(s) and/or center region isidentified (e.g. lit up or coloured), also indicating the detecteddepth(s). In the screenshot shown in FIG. 6B, the processed depth is23.3 ft and the sonar device detected a fish to its left at 12.7 ft.

It is noted that in some embodiments, the sonar data received by theremote computing device is raw sonar data, and thus step 310 isperformed remotely relative to the sonar device, by the remote computingdevice. Alternatively, the processing circuitry of the sonar device maybe configured to identify the underwater objects within each spatialregion, and optionally calculate a depth measured associated with eachunderwater object, and this information may be provided to the remotecomputing device as pre-processed sonar data.

FIG. 7 shows a flow chart illustrating a method of generating andrendering a three-dimensional view of a bed surface (the floor or bottomsurface of a body of water) based on ultrasound signals collected from asonar device employing a pair of angled transducers and a centraltransducer, where the angled transducers are positioned and directed tointerrogate lateral regions (left and right; port and starboard) whenthe sonar device is towed.

As shown in step 500, ultrasound signals are obtained from pair ofangled transducers and the central transducer over a plurality oflongitudinal locations as the sonar device is towed. In step 505, thesignals from the central transducer are processed to generate aplurality of central depth measures corresponding to the differentlongitudinal locations. Similarly, in step 510, the signals from theangled transducers are processed to generate a plurality of lateraldepth measures corresponding to the different longitudinal locations.

These central and lateral depth measures form a grid of discreteestimated depth measures (based on an assumption that the sonar deviceis towed in a straight line), where the grid has three values in thelateral direction (two lateral measures from the angled transducers, andone central measure from the central transducer, and a plurality ofvalues in the longitudinal direction. This grid is then processed, instep 515, and a fitting algorithm (e.g. at least-squares basedpolynomial algorithm) is employed to generate a three-dimensionaltopographical surface model. It will be understand that any knownsurface fitting model may be employed to produce the topographicalmodel, such as those employed in the cartography arts.

In step 520, the topographical surface model is processed to render atopographical surface image that is displayable on a user interface,such that the image shows the three-dimensional features (contours) ofthe surface. Any suitable rendering method may be employed, such asthose known in the computer graphics arts (e.g. perspective-basedrendering methods). It will be understood that even though the actualsurface will have more undulations than those that are rendered, thesimplified rendering will provide the user with useful and simplifiedstructural information, which may be employed to gauge the suitabilityof a location for fishing.

In one example implementation, the topographical surface image isrendered based on a viewpoint located between the bed surface and thewater surface. This rendering may be animated to provide a fly-over viewof the surface. FIG. 8 shows an example of such a rendering.

In some embodiments, the topographical surface image is rendered inreal-time (or near real-time, delayed by processing and communicationtime delays).

The longitudinal direction of the generated image may be based oninferred longitudinal position (e.g. based on a GPS device associatedwith the sonar device or remote computing device), or scaled based onassociated time stamp values.

The specific embodiments described above have been shown by way ofexample, and it should be understood that these embodiments may besusceptible to various modifications and alternative forms. It should befurther understood that the claims are not intended to be limited to theparticular forms disclosed, but rather to cover all modifications,equivalents, and alternatives falling within the spirit and scope ofthis disclosure.

Therefore what is claimed is:
 1. A sonar device, the sonar devicecomprising: a housing configured to float on a top surface of a body ofwater; a power source positioned within the housing; an array oftransducers positioned within the housing, wherein the array oftransducers comprises: a first angled transducer configured to receivefirst sonar return signals; a second angled transducer configured toreceive second sonar return signals; and a central transducer configuredto receive third sonar return signals, wherein the first angledtransducer is aimed at a first non-zero angle relative to the centraltransducer, wherein the second angled transducer is aimed at a secondnon-zero angle relative to the central transducer, wherein each of thefirst sonar return signals, the second sonar return signals, and thethird sonar return signals are different from each other; a wirelesscommunication element configured to transmit one or more signals to andreceive one or more signals from a remote computing device; andprocessing circuitry provided within the housing, wherein the processingcircuitry is configured to: receive the first sonar return signals, thesecond sonar return signals, and the third sonar return signals from thearray of transducers; process the first sonar return signals received bythe first angled transducer to determine a first estimated depthmeasurement corresponding to a first location along a bottom surface ofthe body of water; process the second sonar return signals received bythe second angled transducer to determine a second estimated depthmeasurement corresponding to a second location along the bottom surfaceof the body of water, wherein the second location is different than thefirst location; process the third sonar return signals received by thecentral transducer to determine a third estimated depth measurementcorresponding to a third location along the bottom surface of the bodyof water, wherein the third location is different than both the firstlocation and the second location; generate a topographical surface modelrepresentative of the bottom surface of the body of water by applying afitting algorithm to at least the first estimated depth measurement atthe first location, the second estimated depth measurement at the secondlocation, and the third estimated depth measurement at the thirdlocation; generate a sonar image using the topographical surface model;and transmit, via the wireless communication element, the sonar image tothe remote computing device for presentation on a display of the remotecomputing device.
 2. The sonar device of claim 1, wherein the processingcircuitry is configured to determine the first location, the secondlocation, and the third location based on location data received from alocation sensor at the time in which the first sonar return signals, thesecond sonar return signals, and the third sonar return signals arereceived by the array of transducers.
 3. The sonar device of claim 2,wherein the location sensor is a global positioning system.
 4. The sonardevice of claim 1, wherein the processing circuitry is configured todetermine the first location, the second location, and the thirdlocation based on time stamp values associated with the first sonarreturn signals, the second sonar return signals, and the third sonarreturn signals.
 5. The sonar device of claim 4, wherein the locationsare scaled relative to each other based on the time stamp values.
 6. Thesonar device of claim 1, wherein the topographical surface model is a 3Dtopographical surface model, and wherein the sonar image is a 3D sonarimage.
 7. The sonar device of claim 6, wherein the 3D sonar image isgenerated from a viewpoint located between the bottom surface and thetop surface of the body of water.
 8. The sonar device of claim 6,wherein the processing circuitry is further configured to generate ananimated version of the 3D sonar image so as to provide a fly-over viewof the bottom surface of the body of water.
 9. The sonar device of claim1, wherein the first non-zero angle is opposite the second non-zeroangle with respect to the central transducer.
 10. The sonar device ofclaim 1, wherein the fitting algorithm comprises a least-squares basedpolynomial algorithm.
 11. A system comprising: a sonar devicecomprising: a housing configured to float on a top surface of a body ofwater; a power source positioned within the housing; an array oftransducers positioned within the housing, wherein the array oftransducers comprises: a first angled transducer configured to receivefirst sonar return signals; a second angled transducer configured toreceive second sonar return signals; and a central transducer configuredto receive third sonar return signals, wherein the first angledtransducer is aimed at a first non-zero angle relative to the centraltransducer, wherein the second angled transducer is aimed at a secondnon-zero angle relative to the central transducer, wherein each of thefirst sonar return signals, the second sonar return signals, and thethird sonar return signals are different from each other; a wirelesscommunication element configured to transmit one or more signals to andreceive one or more signals from a remote computing device; andprocessing circuitry provided within the housing, wherein the processingcircuitry is configured to: receive the first sonar return signals, thesecond sonar return signals, and the third sonar return signals from thearray of transducers; process the first sonar return signals received bythe first angled transducer to determine a first estimated depthmeasurement corresponding to a first location along a bottom surface ofthe body of water; process the second sonar return signals received bythe second angled transducer to determine a second estimated depthmeasurement corresponding to a second location along the bottom surfaceof the body of water, wherein the second location is different than thefirst location; process the third sonar return signals received by thecentral transducer to determine a third estimated depth measurementcorresponding to a third location along the bottom surface of the bodyof water, wherein the third location is different than both the firstlocation and the second location; generate a topographical surface modelrepresentative of the bottom surface of the body of water by applying afitting algorithm to at least the first estimated depth measurement atthe first location, the second estimated depth measurement at the secondlocation, and the third estimated depth measurement at the thirdlocation; generate a sonar image using the topographical surface model;and transmit, via the wireless communication element, the sonar image tothe remote computing device for presentation on a display of the remotecomputing device; and the remote computing device comprising: a userinterface comprising a display, wherein the display is configured topresent the sonar image.
 12. The system of claim 11, wherein theprocessing circuitry is configured to determine the first location, thesecond location, and the third location based on location data receivedfrom a location sensor at the time in which the first sonar returnsignals, the second sonar return signals, and the third sonar returnsignals are received by the array of transducers.
 13. The system ofclaim 11, wherein the processing circuitry is configured to determinethe first location, the second location, and the third locationcorresponding to each of the plurality of estimated depth measurementsbased on time stamp values associated with the first sonar returnsignals, the second sonar return signals, and the third sonar returnsignals.
 14. The system of claim 13, wherein the locations are scaledrelative to each other based on the time stamp values.
 15. The system ofclaim 11, wherein the topographical surface model is a 3D topographicalsurface model, and wherein the sonar image is a 3D sonar image.
 16. Thesystem of claim 11, wherein the first non-zero angle is opposite thesecond non-zero angle with respect to the central transducer.
 17. Amethod comprising: receiving, via processing circuitry of a sonardevice, first sonar return signals, second sonar return signals, andthird sonar return signals from an array of transducers of the sonardevice, wherein the sonar device comprises: a housing configured tofloat on a top surface of a body of water; a power source positionedwithin the housing; the array of transducers positioned within thehousing, wherein the array of transducers comprises: a first angledtransducer configured to receive the first sonar return signals; asecond angled transducer configured to receive the second sonar returnsignals; and a central transducer configured to receive the third sonarreturn signals, wherein the first angled transducer is aimed at a firstnon-zero angle relative to the central transducer, wherein the secondangled transducer is aimed at a second non-zero angle relative to thecentral transducer, wherein each of the first sonar return signals, thesecond sonar return signals, and the third sonar return signals aredifferent from each other; a wireless communication element configuredto transmit one or more signals to and receive one or more signals froma remote computing device; and the processing circuitry; processing, viathe processing circuitry, the first sonar return signals received by thefirst angled transducer to determine a first estimated depth measurementcorresponding to a first location along a bottom surface of the body ofwater; processing, via the processing circuitry, the second sonar returnsignals received by the second angled transducer to determine a secondestimated depth measurement corresponding to a second location along thebottom surface of the body of water, wherein the second location isdifferent than the first location; processing, via the processingcircuitry, the third sonar return signals received by the centraltransducer to determine a third estimated depth measurementcorresponding to a third location along the bottom surface of the bodyof water, wherein the third location is different than both the firstlocation and the second location; generating, via the processingcircuitry, a topographical surface model representative of the bottomsurface of the body of water by applying a fitting algorithm to at leastthe first estimated depth measurement at the first location, the secondestimated depth measurement at the second location, and the thirdestimated depth measurement at the third location; generating, via theprocessing circuitry, a sonar image using the topographical surfacemodel; and transmitting, via the wireless communication element, thesonar image to the remote computing device for presentation on a displayof the remote computing device.
 18. The method of claim 17, wherein thetopographical surface model is a 3D topographical surface model, andwherein the sonar image is a 3D sonar image.